How to connect Android app to web server

Question

I am working on designing an Android application for my senior design project. The application will need to be able to connect to a web server. The web server is just a locally hosted Apache web server on a personal computer. The application will need to download a makeshift software update to the phone/application.

At this point in the design, I have the login page and home page built. The problem I am having is how to connect to a web server from the app. My professor has also requested that from the login page, if the proper username and password have been entered, that these credentials will also access the web server. I am also questioning if this is even possible. Any advice will be greatly received.

Thanks - Please let me know if this question needs more info or is not clear enough to answer.

"how to connect to a web server from the app" -- use an HTTP client API (`HttpUrlConnection`, OkHttp, Volley, etc.). "if the proper username and password have been entered, that these credentials will also access the web server" -- set up your Web service API to use the same credentials that you are using for the Web pages. Use those credentials with the HTTP client API. — CommonsWare, Dec 09 '16 at 01:31

Bethan · Answer 1 · 2018-03-14T04:54:42.567

It's very interesting to do the connections of the android to the remote server, very anxiety. Below link will help you max for your need.

Android Connect with Php Mysql

Android Connection using servlets

And If you wanna connect the server from the android device by using HttpUrlConnection then follow the below code.

private static JSONObject get(Context ctx, String sUrl) {
HttpURLConnection connection = null;

try {

    URL url = new URL(sUrl);
    connection = (HttpURLConnection) url.openConnection();
    connection.setRequestProperty("Content-Type", "application/json");
    connection.setRequestProperty("Accept", "application/json");
    connection.setRequestProperty("Authorization",
            "Basic " + encodedAuthentication);
    connection.setRequestProperty("Accept-Charset", "utf-8,*");
    Log.d("Get-Request", url.toString());
    try {
        BufferedReader bufferedReader = new BufferedReader(
                new InputStreamReader(connection.getInputStream()));
        StringBuilder stringBuilder = new StringBuilder();
        String line;
        while ((line = bufferedReader.readLine()) != null) {
            stringBuilder.append(line).append("\n");
        }
        bufferedReader.close();
        Log.d("Get-Response", stringBuilder.toString());
        return new JSONObject(stringBuilder.toString());
    } finally {
        connection.disconnect();
    }
} catch (Exception e) {
    Log.e("ERROR", e.getMessage(), e);
    return null;
}
}

private static String buildSanitizedRequest(String url,
                                        Map<String, String> mapOfStrings) {

Uri.Builder uriBuilder = new Uri.Builder();
uriBuilder.encodedPath(url);
if (mapOfStrings != null) {
    for (Map.Entry<String, String> entry : mapOfStrings.entrySet()) {
        Log.d("buildSanitizedRequest", "key: " + entry.getKey()
                + " value: " + entry.getValue());
        uriBuilder.appendQueryParameter(entry.getKey(),
                entry.getValue());
    }
}
String uriString;
try {
    uriString = uriBuilder.build().toString(); // May throw an
    // UnsupportedOperationException
} catch (Exception e) {
    Log.e("Exception", "Exception" + e);
}

return uriBuilder.build().toString();

}

And Json calling part should look like,

public static JSONObject exampleGetMethod(Context ctx, String sUrl, String username, String password) throws JSONException, IOException {
Map<String, String> request = new HashMap<String, String>();
request.put("username", username);
request.put("password",password);

sUrl = sUrl + "yourApiName";
return get(ctx, buildSanitizedRequest(sUrl, request));
}